Re: [PATCH 2/5] Fonts: Make font size unsigned in font_desc

From: Daniel Vetter <daniel@ffwll.ch>
To: Peilin Ye <yepeilin.cs@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"James E . J . Bottomley" <James.Bottomley@hansenpartnership.com>,
	Helge Deller <deller@gmx.de>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	Jiri Slaby <jirislaby@kernel.org>,
	linux-parisc@vger.kernel.org, dri-devel@lists.freedesktop.org,
	linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] Fonts: Make font size unsigned in font_desc
Date: Tue, 27 Oct 2020 19:50:58 +0100	[thread overview]
Message-ID: <20201027185058.GM401619@phenom.ffwll.local> (raw)
In-Reply-To: <54f7d42e07eca2a2f13669575a9de88023ebc1ac.1603788512.git.yepeilin.cs@gmail.com>

On Tue, Oct 27, 2020 at 12:33:05PM -0400, Peilin Ye wrote:
> It is improper to define `width` and `height` as signed in `struct
> font_desc`. Make them unsigned. Also, change the corresponding printk()
> format identifiers from `%d` to `%u`, in sti_select_fbfont().
> 
> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>

I'm not entirely sure of the motivation here ... height/width should never
ever be even close to the limit here. Or have you seen integer math that
could potentially go wrong if we go with unsigned instead of int?
-Daniel

> ---
> Build-tested.
> 
>  drivers/video/console/sticore.c | 2 +-
>  include/linux/font.h            | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/video/console/sticore.c b/drivers/video/console/sticore.c
> index 6a26a364f9bd..d1bb5915082b 100644
> --- a/drivers/video/console/sticore.c
> +++ b/drivers/video/console/sticore.c
> @@ -502,7 +502,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
>  	if (!fbfont)
>  		return NULL;
>  
> -	pr_info("STI selected %dx%d framebuffer font %s for sticon\n",
> +	pr_info("STI selected %ux%u framebuffer font %s for sticon\n",
>  			fbfont->width, fbfont->height, fbfont->name);
>  			
>  	bpc = ((fbfont->width+7)/8) * fbfont->height; 
> diff --git a/include/linux/font.h b/include/linux/font.h
> index b5b312c19e46..4f50d736ea72 100644
> --- a/include/linux/font.h
> +++ b/include/linux/font.h
> @@ -16,7 +16,7 @@
>  struct font_desc {
>      int idx;
>      const char *name;
> -    int width, height;
> +    unsigned int width, height;
>      const void *data;
>      int pref;
>  };
> -- 
> 2.25.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch